Electric lamp



WQ L@ VOELKER.

ELECTRIC LAMP.

' No. 253,645. Patented Peb. 14,1882.'

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WILLIAM L. VOELKER, OF MORTON, PENNSYLVANIA.

ELECTRIC LAMP.

SPECIFICATION'forming vpart of Letters Patent No. 253,645, dated February 14, 1882.

Application filed J une 24, 1881. (No model.)

To all whom it may concern:

Be it known that I, WILLIAM L. VOELKER, of Morton, in the county of Delaware and State of Pennsylvania, have invented certain new and useful Improvements in Electric Lamps, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings and the letters marked thereon.

My improved electric lamp belongs4 to that class commonly known as incandescent, and hasV for its 'object the production of a device simple and easy to construct, wherein the parts are few in number, and are of such form and character as to be easily handled and placed in position for uniting in order to complete the lamp.

Hitherto in vmanufacturing lamps of this description greatl difficulty has been experienced by the artisan in constructing the parts in such manner as to prevent fracture of the delicate filament of carbon employed, or other parts of the lamp while manipulating the same, a large number being destroyed before completion, thereby rendering the cost of the lamp too great for practical purposes; but by my method of construction these obstacles are overcome, and the lamp may be produced at a greatly-reduced cost; and my invention involves certain novel and useful combinations or arrangements of parts and peculiarities of construction and operation, all of which will behereinafter first fully described, and then pointed out in the claims.

In the drawings, Figure 1 is a view of the filament of carbon and its connections. Fig. 2 is a View of the glass bulb forming the walls of the lamp as first formed. Fig.3 shows the position of the various parts and the method of manipulation, and Fig. et shows the completed lamp.

Like letters of reference, wherever they oc cur, indicate corresponding parts in all the figures.

Ais a filament of carbon, formed in the usual manner. B are platinum connections between said carbon and the exterior of the lamp. In uniting the carbon and platinum I first electroplate the ends of the carbon, and then by means of hard or silver solder easily secure them together, as indicated ata. From the facility with which this operation may be by means of solder, said blocks being adapted Y and arranged to hold a short rod of carbon therebetween by pressure. My lamp is of entirely different construction. Theincandescing filament of carbon is united directly to the conducting or supporting wires within thelamp, said wires being sealed into the glass at the bottom of the tube through which they pass.

By this means I obtain a continuous circuit uninterrupted by bad joint-s, and there is no danger ot' the formation of minute arcs l.

'at the extremities of the carbon filament.

. C is a small ball, of glassor other non-conducting material, of such nature as to with- 'stand a considerable degree of heat before melting. This ball is compressed around the wires by means of heat in such a manner as ito separate them the necessary distance from each other' and hold them in a secure position. In preparing the platinum connectionsl make them considerablylon ger than will be required in the completed lamp, and secure to their lower extremities a rod, C', of glass or other suitable material, and of suitable length. By use ot' rod C the carbon and its connections may be freely handled while adjusting.

Fig. 2 shows a. bulb of glass,D7 as prepared for the reception of the interior parts of the lamp and the connections with the exterior. Said bulb is surmounted by a short section of large tubing,D, of such diameter as to permit the free passage therethrough of the carbon when formed in the desired shape.

D2 is a small glass tube forming the base of the lamp. It is of such size as to permit the passage of the rod C and the platinum connections. In placing the part-s in position, rod C is passed down through the bulb from the top through tube D2; then by grasping said rod the carbon may be easily drawn down to its position in the bulb, the ball C resting in the neck of the lamp, as shown. From its position upon the connections below the carbon, ball C will be found of great service in locating thesame in the exact position required. Tube D2 is now sealed around the wires and rod C removed. When the carbon is secured in place, a's above described, to tube D is united a short section ot' corresponding size, as indicated in Fig. 3 by the dotted lines, and the bulb is drawn together at top in the usual mauner and a short piece of capillary tube, E, at'- xed thereto. The air is then exhausted from the bulb through tube E by means of the airpump, and tube E is closed at E. Upon being removed from the pump said tube is again closed at E2 and the remainder drawn off.

Fig. 4 shows the completed lamp. It may be supported at bottom in any desired manner by a screw-threaded collar secured to tube D2, or, instead of being screw-threaded, the collar may be made smooth and arranged to fit into a socket in the support.

I am aware that electric lamps have been constructed having two long tubes leading downward from the bulb, said: tubes being affixed thereto'after the insertion of a dat base for supporting the filament of carbon, the conductors extending downward therefrom into mercury contained in said tubes. `In practice it will be found that as nomeans are provided for holding' the supporting-base in place, and as the conductors simply hang in the mercury, the interiorV parts of the lamp easily become displaced and the iila'ment of carbon broken. Lampshave also been constructed with a glass support for the conductors extending upward a short'distance within the bulb. The' massof glass is so great that it quickly destroys the lamp by reason of the undueexpansion under heat. Again', the support is so slight as' to allow the carbon to be easily become vdisplaced and broken. These difficulties are overcome in my` improved construction, as the carbon and its support p ass into the bulb at the top, and the ball of refractory material tinds a seat prepared for its reception in the neck 'of the bulb, and the two conductors, extending downward side by side and being securely sealed into the glass p at bottom, hold the support and carbon firmly in position, rendering displacement impossible.

From the above description it will be seen that my improved method of constructing incandescent lamps is calculated to greatly reduce the cost thereof, as there is very little danger of breaking the same while manipulating in the course of manufacture, and the completed device admirably answers the various uses andpurposes for which it is intended.

Having now fully described my invention, what I claim as new therein, and desire to secure by Letters Patent, is-

1. In an electric lamp of the character herein specified, the incandescin g filament of carbon A, plated atits extremities and united by means of solder to the extremities of platinum conducting-supports B, extending to the exterior ofthe lamp and held in place by a spherical mass of non-conducting material, C, seated in theneck of the. globe, said conductors B and( incandescin g filament A forming a continuous unbroken conductor, substantially as shown and described.

2. In an incandescent electric lamp of the character herein specified, the combination, with the transparent bulb and neck formed in onempiece, of a spherical mass of non-conductingmaterial seated iu the neck, the two conductingsupportsfor the carbon filament secured in said mass and passing downward side by side a slight distance apart from each other through the neck of the bulb, said neck being sealed around the conductors at its lower extremity, substantiallyl as shown and described.

In testimony that I claim the foregoing I have hereunto set myhand in the presence of 8o two' witnesses. n 'WILLIAM L. voELKEa Witnesses:

F. W. HANAFORD, A. M. PIERCE. 

